Superlinear perturbations of the eigenvalue problem for the Robin Laplacian plus an indefinite and unbounded potential
arXiv:2008.05740 · doi:10.1007/s00025-020-01234-z
Abstract
We consider a superlinear perturbation of the eigenvalue problem for the Robin Laplacian plus an indefinite and unbounded potential. Using variational tools and critical groups, we show that when is close to a nonprincipal eigenvalue, then the problem has seven nontrivial solutions. We provide sign information for six of them.